Members of the minority groups are being singled out by extremist insurgent groups and also are caught in the middle of a struggle for land and resources between Arabs and the central government on one hand and leaders of Iraq's semi-autonomous Kurdish region on the other, said the report, which was released Tuesday in the Kurdish region's capital, Erbil, and focused on Christians, Shabaks and Yazidis in Nineveh province.

The extremist attacks have cost many hundreds of lives and, the report notes, "struck at the social infrastructure of minority communities, leaving victims and others fearful to carry on with their everyday lives."

The report is particularly critical of the policies and tactics pursued by Kurdish authorities who control Nineveh's disputed territories through the presence of their security forces and political party offices. The report describes how the Kurdish government has sought to repress minorities, subsume the identity of Shabaks and Yazidis into that of Kurds and sow rifts within the groups with bribes and patronage while suppressing dissent through violence, torture, arrests and killings.

The U.S. military has recognized the Arab-Kurdish conflict in northern Iraq as the main driver for continued instability in Iraq.

After a series of bombings in July and August against minorities in Nineveh that killed at least 143, wounded scores and flattened villages, the U.S. military commander in Iraq, Gen. Ray Odierno, announced plans to deploy U.S. troops along with members of the Kurdish peshmerga force and the Iraqi army in the disputed areas to stop groups linked to al-Qaida from exploiting friction between Arabs and Kurds.